Prior commercial methods for achieving durable press properties in textile fabrics typically have used aminoplast resins, such as glyoxal resin, melamine resin, urons, carbamates and urea formaldehydes as the reactive durable press finishing agents in a treatment process which involves impregnating the fabric with an aqueous solution of the resin, and thereafter drying the fabric and curing and crosslinking the resin. Since these aminoplast resins are all based on formaldehyde, the durable press treatment processes which use these resins result in formaldehyde being evolved from the fabric during the curing operation, and also result in the presence of free formaldehyde in the resulting fabric.
Because of concern over health hazards presented by exposure to formaldehyde, there has been a great deal of recent interest in developing a durable press treatment process which does not involve the use of formaldehyde or formaldehyde based resins and does not result in the presence of formaldehyde in the curing operation or in the resulting fabric. By way of example, recent U.S. patents concerned with nonformaldehyde durable press treatment processes include the following: U.S. Pat. Nos. 4,076,870; 4,116,625; 4,269,602; and 4,269,603.
While these patents disclose various approaches to the elimination of formaldehyde in durable press processing, the processes all have certain limitations or disadvantages which make them undesirable for use on a commercial scale, and hence, insofar as applicants are aware, these processes have not been used commercially to any significant extent. Accordingly, an object of the present invention is to provide a new and improved formaldehyde-free process for obtaining durable press properties in a textile fabric.
The present invention is based upon use of silicone compounds as a durable press agent for producing durable press properties in a textile fabric without the use of formaldehyde or formaldehyde based resins. Silicone polymers have been used heretofore in textile finishing operations as softeners to impart a better hand to the fabric and for imparting water repellent properties. Silicones have also been used in conjunction with aminoplast resins such as those described above in durable press treatment processes as extenders to reduce the amount of aminoplast resin required. Attempts have also been made to use silicone polymers alone for imparting durable press properties to certain types of fabric. Such attempts are disclosed for example in British Pat. No. 1,123,447 and Canadian Pat. No. 862,635. In these prior approaches, silicone polymers are applied to the fabric and cured or vulcanized to form a permanent resilient sheath on the textile fibers. Apparently, the resilient flexible nature of the silicone polymer sheath is intended to enhance the crease recovery of the fibers and thereby impart durable press properties. However, these prior approaches have been unsuccessful in providing a silicone based durable press textile treatment for use on textile fabrics containing cellulosic fibers which is suitable for commercial production using conventional pad-dry-cure techniques.